After a compressor for vehicle air conditioning is manufactured at a factory, lubricating oil is enclosed in the interior of the compressor. In the housing of the compressor, a suction port and a discharge port are formed at a connection portion, which is connected to external piping. After enclosing the lubricating oil, a seal cap, which is made of rubber or plastic, is press-fitted into the suction port and the discharge port so that the suction port and the discharge port are sealed by the seal cap.
As a conventional seal cap, a dustproof cap has been known that is used in a vehicle air conditioner as disclosed in Patent Document 1. As shown in FIG. 10, the vehicle air conditioner includes a connection block 100 at an end of a set of piping through which refrigerant flows. In the connection block 100 are opened a first hole portion 101 and a second hole portion 102, which are in communication with the set of piping. A dustproof cap 103 for preventing entry of dust into an interior of an evaporator through the first hole portion 101 and the second hole portion 102 is installed on the connection block 100. The dustproof cap 103 is formed by a body 106 and a hook portion 107. The body 106 has a first fitting portion 104 and a second fitting portion 105, which seal the first hole portion 101 and the second hole portion 102, respectively. The hook portion 107 is formed to project from the body 106. The hook portion 107 is pulled when the body 106 is to be detached from the connection block 100. The hook portion 107 is formed to be rotational with respect to the body 106.
Patent Document 2 discloses another conventional sealing device. The sealing device is used in a compressor, in which a suction port and a discharge port are opened in a connection portion connected to piping and a stud bolt for fixing a piping connection member is fixed to a vicinity of each port. The sealing device seals the suction port or the discharge port. The sealing device has a seal body fitted to the suction port or the discharge port in an airtight manner, tubular bodies surrounding the periphery of the stud bolts, and a lug portion formed integral to the seal body and the tubular bodies. A slit that extends in an axial direction from a base of the tubular body is formed in a peripheral wall of the tubular body.